- ID:
- ivo://CDS.VizieR/J/A+A/642/A192
- Title:
- C3R2-KMOS zsp & galaxy physical properties
- Short Name:
- J/A+A/642/A192
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Complete Calibration of the Colour-Redshift Relation survey (C3R2) is a spectroscopic effort involving ESO and Keck facilities designed specifically to empirically calibrate the galaxy colour-redshift relation - P(zjC) to the Euclid depth (i_AB_=24.5) and is intimately linked to the success of upcoming Stage IV dark energy missions based on weak lensing cosmology. The aim is to build a spectroscopic calibration sample that is as representative as possible of the galaxies of the Euclid weak lensing sample. In order to minimise the number of spectroscopic observations necessary to fill the gaps in current knowledge of the P(zjC), self-organising map (SOM) representations of the galaxy colour space have been constructed. Here we present the first results of an ESO@VLT Large Programme approved in the context of C3R2, which makes use of the two VLT optical and near-infrared multi-object spectrographs, FORS2 and KMOS. This data release paper focuses on high-quality spectroscopic redshifts of high-redshift galaxies observed with the KMOS spectrograph in the near-infrared H- and K-bands. A total of 424 highly-reliable redshifts are measured in the 1.3<=z<=2.5 range, with total success rates of 60.7% in the H-band and 32.8% in the K-band. The newly determined redshifts fill 55% of high (mainly regions with no spectroscopic measurements) and 35% of lower (regions with low-resolution/low-quality spectroscopic measurements) priority empty SOMgrid cells.We measured H fluxes in a 1.2" radius aperture from the spectra of the spectroscopically confirmed galaxies and converted them into star formation rates. In addition, we performed an SED fitting analysis on the same sample in order to derive stellar masses, E(B-V), total magnitudes, and SFRs. We combine the results obtained from the spectra with those derived via SED fitting, and we show that the spectroscopic failures come from either weakly star-forming galaxies (at z<1.7, i.e. in the H-band) or low S/N spectra (in the K-band) of z>2 galaxies.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/778/98
- Title:
- Cross-correlation of SDSS QSOs and BOSS galaxies
- Short Name:
- J/ApJ/778/98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the measurement of the two-point cross-correlation function (CCF) of 8198 Sloan Digital Sky Survey Data Release 7 quasars and 349608 Data Release 10 CMASS galaxies from the Baryonic Oscillation Spectroscopic Survey (BOSS) at 0.3<z<0.9. The CCF can be reasonably well fit by a power-law model {xi}_QG_(r)=(r/r_0_)^-{gamma}^ on projected scales of r_p_=2-25h^-1^Mpc with r_0_=6.61+/-0.25h^-1^Mpc and {gamma}=1.69+/-0.07. We estimate a quasar linear bias of b_Q_=1.38+/-0.10 at <z>{=}0.53 from the CCF measurements, which corresponds to a characteristic host halo mass of ~4x10^12^h^-1^M_{sun}_, compared with a ~10^13^h^-1^M_{sun}_ characteristic host halo mass for CMASS galaxies. Based on the clustering measurements, most quasars at {overline}{z}~0.5 are not the descendants of their higher luminosity counterparts at higher redshift, which would have evolved into more massive and more biased systems at low redshift. We divide the quasar sample in luminosity and constrain the luminosity dependence of quasar bias to be db_Q_/dlogL=0.20+/-0.34 or 0.11+/-0.32 (depending on different luminosity divisions) for quasar luminosities -23.5>M_i_(z=2)>-25.5, implying a weak luminosity dependence of clustering for luminous quasars at {overline}{z}~0.5. We compare our measurements with theoretical predictions, halo occupation distribution (HOD) models, and mock catalogs. These comparisons suggest that quasars reside in a broad range of host halos. The host halo mass distributions significantly overlap with each other for quasars at different luminosities, implying a poor correlation between halo mass and instantaneous quasar luminosity. We also find that the quasar HOD parameterization is largely degenerate such that different HODs can reproduce the CCF equally well, but with different satellite fractions and host halo mass distributions. These results highlight the limitations and ambiguities in modeling the distribution of quasars with the standard HOD approach.
- ID:
- ivo://CDS.VizieR/J/ApJ/841/111
- Title:
- C3R2 survey: high-confidence redshifts from DR1
- Short Name:
- J/ApJ/841/111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A key goal of the Stage IV dark energy experiments Euclid, LSST, and WFIRST is to measure the growth of structure with cosmic time from weak lensing analysis over large regions of the sky. Weak lensing cosmology will be challenging: in addition to highly accurate galaxy shape measurements, statistically robust and accurate photometric redshift (photo-z) estimates for billions of faint galaxies will be needed in order to reconstruct the three-dimensional matter distribution. Here we present an overview of and initial results from the Complete Calibration of the Color-Redshift Relation (C3R2) survey, which is designed specifically to calibrate the empirical galaxy color-redshift relation to the Euclid depth. These redshifts will also be important for the calibrations of LSST and WFIRST. The C3R2 survey is obtaining multiplexed observations with Keck (DEIMOS, LRIS, and MOSFIRE), the Gran Telescopio Canarias (GTC; OSIRIS), and the Very Large Telescope (VLT; FORS2 and KMOS) of a targeted sample of galaxies that are most important for the redshift calibration. We focus spectroscopic efforts on undersampled regions of galaxy color space identified in previous work in order to minimize the number of spectroscopic redshifts needed to map the color-redshift relation to the required accuracy. We present the C3R2 survey strategy and initial results, including the 1283 high-confidence redshifts obtained in the 2016A semester and released as Data Release 1.
- ID:
- ivo://CDS.VizieR/J/A+A/416/111
- Title:
- C stars in Wolf-Lundmark-Melotte galaxy
- Short Name:
- J/A+A/416/111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used the CFH12K wide field camera to survey the carbon star population of the Wolf-Lundmark-Melotte system using the CN-TiO technique. 149 C stars are identified with a mean <I>=20.28, corresponding to <M_I_>=-4.65, a mean luminosity similar to what we found in other irregular galaxies. Star counts in and around the main body of WLM reveal that its stellar distribution is quite elliptical ({epsilon}=0.58) with major and minor axes of 26' and 11'. Comparison of the density profile of C stars and old red giants shows that their scale lengths differ by only 15% pointing to mixed populations. Wolf-Lundmark-Melotte is found to be unique among dwarf irregular galaxies by having essentially a handful of early-type AGB M stars thus leading to an extreme C/M ratio.
- ID:
- ivo://CDS.VizieR/J/AJ/121/2020
- Title:
- CTIO and WFPC2 photometry in NGC 6822
- Short Name:
- J/AJ/121/2020
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the massive star population of NGC 6822 with ground-based UBV photometry covering the whole of the galaxy and HST WFPC2 photometry with filters F255W, F336W, F439W, and F555W of two fields containing very rich and crowded OB associations. The four-band WFPC2 photometry is used to derive Teff and E(B-V). H-R diagrams are constructed for the OB associations included in our fields. These show that 10Myr old populations are present in OB 9 and OB 6, while more recent star formation have occurred in OB 8, OB 13, OB 15, and OB 7. Two particularly interesting H II regions, Hubble V and Hubble X, are included in our fields. The luminous massive stars that power these bright H II regions (H{alpha} luminosity several times that of the Orion nebula), could be resolved even in their dense cores thanks to the HST spatial resolution. Our data reveal very young (a few million years), apparently coeval populations, with several massive star candidates.
- ID:
- ivo://CDS.VizieR/J/MNRAS/382/1947
- Title:
- CT1 photometry in NGC 1399 and NGC 4486
- Short Name:
- J/MNRAS/382/1947
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper explores the quantitative connection between globular clusters and the diffuse stellar population of the galaxies they are associated with. Both NGC 1399 and NGC 4486 (M87) are well suited for this kind of analysis due to their large globular cluster populations. The main assumption of our Monte Carlo based models is that each globular cluster is formed along with a given diffuse stellar mass that shares the same spatial distribution, chemical composition and age. The main globular cluster subpopulations, that determine the observed bimodal colour distribution, are decomposed avoiding a priori parametric (e.g. Gaussian) fits and using a new colour (C-T1)-metallicity relation. The eventual detectability of a blue tilt in the colour-magnitude diagrams of the blue globular cluster subpopulation is also addressed.
- ID:
- ivo://CDS.VizieR/J/ApJ/662/808
- Title:
- Cusp radius in luminous elliptical galaxies
- Short Name:
- J/ApJ/662/808
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Black hole (BH) masses predicted from the M_BH_-sigma relationship conflict with predictions from the M_BH_-L relationship for high-luminosity galaxies, such as brightest cluster galaxies (BCGs). The M_BH_-L relationship predicts that some BCGs may harbor BHs with M_BH_ approaching 10^10^M_{sun}_ while the M_BH_-sigma relationship always predicts M_BH_<3x10^9^M_{sun}_. We argue that the M_BH_-L relationship is a plausible description for galaxies of high luminosity. If the cores in central stellar density are formed by binary BHs, the inner core cusp radius, r{gamma}, may be an independent witness of M_BH_. Using central structural parameters derived from a large sample of early-type galaxies observed by HST, we argue that L is superior to sigma as an indicator of r{gamma}.
- ID:
- ivo://CDS.VizieR/J/MNRAS/359/930
- Title:
- CUYS survey of Ha+NII ELG galaxies
- Short Name:
- J/MNRAS/359/930
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the CIDAUCMYale (Centro de Investigaciones de Astronomia, Universidad Complutense de Madrid, and Yale University) Survey (CUYS) for H{alpha}+[NII] 6549, 6584{AA} emission-line galaxies (ELGs) using objective-prism spectra. The most important properties of a catalogue with 427 entries and significant subsets are analysed. The complete sample contains 183 statistically confirmed ELGs in a sky area of 151deg^2^ and redshift up to 0.14. We determine the parameters of the H{alpha} luminosity function using the H{alpha}+[NII] flux directly measured on the ELG spectra in this sample, and the star formation rate density derived is in agreement with values reported in the literature.
- ID:
- ivo://CDS.VizieR/J/MNRAS/488/2175
- Title:
- CVRHS classifications for 719 AMIGA galaxies
- Short Name:
- J/MNRAS/488/2175
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using images from Sloan Digital Sky Survey Data Release 8, we have re-examined the morphology of 719 galaxies from the Analysis of the interstellar Medium in Isolated GAlaxies (AMIGA) project, a sample consisting of the most isolated galaxies that have yet been identified. The goal is to further improve the classifications of these galaxies by examining them in the context of the Comprehensive de Vaucouleurs revised Hubble-Sandage (CVRHS) system, which includes recognition of features that go beyond the original de Vaucouleurs point of view. Our results confirm previous findings that isolated galaxies are found across the complete revised Hubble sequence, with intermediate to late-type (Sb-Sc) spirals being relatively more common. Elmegreen Arm Classifications are also presented, and show that more than 50\% of the 514 spirals in the sample for which an arm class could be judged are grand design (AC 8,9,12). The visual bar fraction for the sample is ~50%, but only 16% are classified as strongly-barred (SB). The dominant family classification is SA (nonbarred), the dominant inner variety classification is (s) (pure spiral), and the dominant outer variety classification is no outer ring, pseudoring, or lens. The Kolmogorov-Smirnov test is used to check for potential biases in the morphological interpretations, and for any possible relation between rings, bars, and arm classes with local environment and far-infrared excess. The connection between morphology and stellar mass is also examined for a subset of the sample.
- ID:
- ivo://CDS.VizieR/J/MNRAS/488/590
- Title:
- CVRHS classifications for the EFIGI Galaxy Sample
- Short Name:
- J/MNRAS/488/590
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is the third which examines galaxy morphology from the point of view of comprehensive de Vaucouleurs revised Hubble-Sandage (CVRHS) classification, a variation on the original de Vaucouleurs classification volume that accounts for finer details of galactic structure, including lenses, nuclear structures, embedded disks, boxy and disky components, and other features. The classification is applied to the EFIGI sample, a well-defined set of nearby galaxies which were previously examined by Baillard et al. (2011, Cat. J/A+A/532/A74) and de Lapparent et al. (2011A&A...532A..75D). The survey is focussed on statistics of features, and brings attention to exceptional examples of some morphologies, such as skewed bars, blue bar ansae, bar-outer pseudoring misalignment, extremely elongated inner SB rings, outer rings and lenses, and other features that are likely relevant to galactic secular evolution and internal dynamics. The possibility of using these classifications as a training set for automated classification algorithms is also discussed.